Flight for collecting sludge by sweeping and roller shoe fixed thereto

Abstract

A flight for collecting sludge by sweeping comprises a roller shoe, comprising (a) a frame having a substantially U-shaped cross section and having a pair of side plates, (b) a shaft having a diameter-enlarged portion at one end and a threaded portion at the other end, and fixed to the side plates, and (c) a roller rotatably supported by the shaft between the side plates, wherein the frame is constituted by an injection-molded synthetic resin, and the roller is made of a synthetic resin.

What is claimed is: 
     
       1. A roller shoe fixed to a flight for collecting sludge by sweeping, comprising: (a) a frame having a substantially U-shaped across section, which has a pair of side plates, one side plate being provided with a first aperture, a first annular outward projection around said first aperture and a first center recess inside said first annular outward projection, and the other side plate being provided with a second aperture, a second annular outward projection around said second aperture and a second center recess inside said second annular outward projection;   (b) a shaft having a diameter-enlarged portion at one end and a threaded portion at the other end, said diameter-enlarged portion portion engaging said first center recess without projecting from said first annular outward projection such that the rotation of said shaft is prevented, and said threaded portion projecting from said second aperture and being fastened to a threading means inside said second center recess so that said shaft is fixed to said frame; and   (c) a roller rotatably supportd by said shaft between the side plates, wherein said frame is constituted by an injection-molded synthetic resin, and said roller is made of a synthetic resin.     
     
     
       2. A flight for collecting sludge by sweeping comprising a roller shoe fixed thereto, said roller shoe comprising: (a) a frame having a substantially U-shaped cross section, which has a pair of side plates, one side plate being provided with a first aperture, a first annular outward projection around said first aperture and a first center recess inside said first annular outward projection, and the other side plate being provided with a second aperture, a second annular outward projection around said second aperture and a second center recess inside said second annular outward projection;   (b) a shaft having a diameter-enlarged portion at one end and a threaded portion at the other end, said diameter-enlarged portion engaging said first center recess without projecting from said first annular outward projection such that the rotation of said shaft is prevented, and said threaded portion projecting from said second aperture and being fastened to a threading means inside said second center recess so that said shaft is fixed to said frame; and   (c) a roller rotatably supported by said shaft between the side plates, wherein said flight is made of fiber-reinforced plastics, said frame is constituted by an injection-molded synthetic resin, and said roller is made of a synthetic resin.